Wheels..... Just when I thought I had it solved

I've been keeping my eyes out for quite some time, trying to find a good deal on a set of 15" Magnums, for a '70 fastback I'm going to sell. The other day I came across an ad on CL for a set of 15" tires that were "Like New". Being of a curious nature, and seeing the ad claimed they were close to me, I went ahead and clicked on it..... The ad talked up a set of "off brand" tires, and discreetly mentioned they came with a set of "Mustang Wheels"? After scrolling down, and examining his pictures, there was one picture that stood out. showing a tire mounted, at a distance on a Magnum? Hmmm..... after making contact with the seller, He begins to try to sell me on these tires, so I quickly explain that my real interest is in the wheels, and what they came off of. He explains they were on his '67, but were too big, and rubbed on the front? So, with this little knowledge, I hopped in my truck, to go check them out. Upon my arrival, I find him waiting in his driveway, aside his prized tires...After our introductions, he quickly explains to me, how he had Payed way to much for the wheels, and had been "Taken" in the deal. He shows me that he even had to replace one wheel, and that it was "New". Hmmm.... The other three seemed to resemble the "new" one, but it was hard to tell because they were so grimey? The back spacing looked correct, and the rims did not appear to have any rust pits. So with an attractive price that I felt I could survive I made the deal for them. Today I went to clean them up, and prepare to have them dismounted. As I cut through the grime on the three used wheels, I noticed that the center had a dull finish... I grabbed my glasses for a closer look... Although the rims were shiny Chrome, the centers looked like a satin chrome finish. I than noticed that these three rims were 15" x 7", while the new one was an 8". Starting to become less enthused with my purchase, I quickly decide all is not lost, because I can purchase one 8" wheel, and have the extra 7" for a spare! So back to cleaning I go! After scrubbing all the fronts, I take on the Task of the back side. The "New" one was so easy, why did the others have to be so grubby? I grabbed a box of SOS, and went to work making a thick dark lather, beginning to see streaks of shine I continued diligently, till the gunky mess became so annoying that I needed to rinse it all away, just to see what I was doing. I grabbed the hose with my slippery hands, and fought to twist the nozzle. After rinsing the sludge from my hands, I turned the hose on the scummy mess that was hiding my unfinished task. As the water washed away the sludge, I could see something shining beneath. I was just starting to feel a sense of accomplishment, when I noticed something else... What now I thought? Once again repeating the SOS, and rinse, there in front of me was the Ford Logo in it's little Oval, and it's adjacent numbers. After a brief recess and reality check, It appears that I now possess three 1970 boss 302 wheels, and one repop. Here's my Dilemma....Knowing that I just wanted some period correct rims to aid in the sale of this car, I hate to waste these rims on it. what are your thoughts? Any advise will be greatly appreciated.

Hmmm.... Great minds think alike! I threw them out on CL, and have already had several bites. I just took the tires off, as I sold them yesterday to a Oldsmobile owner. So now I'm just sitting back...... Right Where I Started!